Rosemary Monica Wanjiru (born 9 December 1994) is a Kenyan professional female long-distance runner who competes in the 5000 metres and 10,000 metres. She was the silver medallist in the 5000 m at the 2015 African Games, and represented her country at the 2019 World Athletics Championships, finishing fourth in the 10,000 m. Wanjiru achieved the second-fastest ever women's marathon debut at the 2022 Berlin Marathon.